نتایج جستجو برای: equivalent hydraulic conductivity

تعداد نتایج: 212988  

2003
Christian D. Langevin

The generalized conceptual model for a fractured bedrock aquifer consists of low-permeability matrix blocks separated by highly permeable fractures that act as preferential pathways for ground water flow. The National Research Council (NRC 1996) summarizes three approaches for simulating ground water flow in fractured aquifers. The most common approach is to represent the system with an equival...

2017
Alaa H. Aly R. C. Peralta

We present a methodology to account for the stochastic nature of hydraulic conductivity during the design of pump-and-treat systems for aquifer cleanup. The methodology (I) uses a genetic algorithm to find the global optimal solution and (2) incorporates a neural network to model the response surface within the genetic algorithm. We apply the methodology for a real example and different optimiz...

Journal: Geopersia 2016

IInfiltration rate and hydraulic conductivity are immensely important parameters for evaluating the hydrology of subsurface environments. Specifically, in disposal wells schemes and in artificial recharge plans both properties must be correctly assessed to better analyze the performance of these installations. In a new research, tanker water and rainfall runoff were injected into a 22.5 m deep ...

1998
Hongbin Zhan

Contaminant transport in a strongly heterogeneous stratified formation whose log hydraulic conductivity distribution has a variance greater than unity is investigated. Four kinds of waste leakage scenario are studied. They are: (1) continuous waste leakage from landfills; (2) temporal waste leakage from landfills; (3) continuous deepwell injection wastes; and (4) temporal deep-well injection wa...

Journal: :تحقیقات مهندسی کشاورزی 0
فریبرز عباسی دانشیار مؤسسه تحقیقات فنی و مهندسی کشاورزی

soil hydraulic properties are key soil physical characteristics that are required to conduct soil and water related studies such as irrigation and drainage. in this study, three indirect methods: inverse modeling, pedo-transfer function, and the semi-physical method of arya et al., were compared in a sandy loam soil to estimate soil moisture retention and unsaturated hydraulic conductivity curv...

2000
M. Inoue S. Shiozawa J. W. Hopmans

Estimation of soil hydraulic and solute transport parameters is important to provide input parameters for numerical models simulating transient water ̄ow and solute transport in the vadose zone. The Levenberg±Marquardt optimization algorithm in combination with the HYDRUS-1D numerical code was used to inversely estimate unsaturated soil-hydraulic and solute transport parameters from transient m...

2001
Michael Raviv J. Heinrich Lieth Rony Wallach

Rose plants (Rosa x hybrida L. CV. Kardinal, grafted on Natal Brier) were grown in UC mix and in coconut coir. Water release curves and hydraulic conductivity of the media were measured. Water tensions in the media were maintained within a predetermined narrow range by tension-actuated irrigation, using high-flow electronic tensiometers. Transpiration rate of plants sitting on load cells was me...

Journal: :Journal of contaminant hydrology 2009
Bill X Hu Mark M Meerschaert Warren Barrash David W Hyndman Changming He Xinya Li Luanjing Guo

It is widely recognized that groundwater flow and solute transport in natural media are largely controlled by heterogeneities. In the last three decades, many studies have examined the effects of heterogeneous hydraulic conductivity fields on flow and transport processes, but there has been much less attention to the influence of heterogeneous porosity fields. In this study, we use porosity and...

2001
Jan W. Hopmans

In order to better manage and monitor fluid flow and migration of chemicals in gas and liquid phases, a fundamental understanding and knowledge of the saturation dependency of permeability, diffusion and electrical conductivity in a porous medium is required. The initial fundamental formulations and recent research for characterization of transport properties in porous media are discussed. To i...

2005
MARY ANNE SWORD

Comparison of the root system growth and water transport of southern pine species after planting in different root-zone environments is needed to guide decisions regarding when, and what species to plant. Evaluation of how seed source affects root system responses to soil conditions will allow seed sources to be matched to planting conditions. The root growth and hydraulic conductivity of three...

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